import {sum} from './math'
// import count from "./count";
console.log('main.js');
console.log(sum(1,2,3));
document.getElementById('btn').onclick = function () {
  // import动态导入按需加载
  import('./count')
    .then(res => {
      console.log(`加载成功${res}`);
      console.log(res.default(2,1));
    })
    .catch(res =>{
      console.log(`加载失败${res}`);
    })
  console.log(this);
}